In the years 1675-1864, the Congregation of the Mission managed 27 diocesan seminaries in Poland. Over the course of nearly 200 years, their number fluctuated (24-22), and their share in the total number of diocesan seminaries dropped from 75% in the 18th century to 65% in the 19th century. Because the issues of the curriculum (ratio studiorum) and the intellectual formation of graduates was already discussed in another article, this study attempts to examine two issues: the process of spiritual formation of graduates and the way in which they were prepared for their pastoral role. The author examines the religious life of graduates, their prayer books, the topics of religious conferences they attended as part of the curriculum, customs regarding confession and Holy Communion, and participation in special retreats (their frequency and topics). The graduates prepared to conduct catechesis for children and adults, preach sermons and teach parishioners about their participation in the life of the Church (participating in masses, special services with religious rites, familiarizing them with Polish hymns and songs sung in church). The article also considers theoretical aspects of the pastoral formation of graduates, as well as their first practical experiences in teaching and preaching. Examining sources from the seminary archives allows us to trace the mixed reactions of the Vincentian community to new philosophical and theological ideas from Western Europe. While some of them were criticized and rejected, others, such as Jansenism, left their mark on pastoral formation. The study of the sources gives an interesting insight into the formation of Polish religious mentality in the 18th and 19th centuries. The article also touched upon problems related to transmitting the teachings of Vincentian spirituality to graduates, with an emphasis on caring for the poor, sick and socially needy.